Instantiating talkgroups

ABSTRACT

In one implementation, information specifying a geographic area for a talkgroup may be received. In addition, information specifying that the talkgroup is a “warm” talkgroup may be received. In response to the receipt of the information specifying that the talkgroup is a “warm” talkgroup, a satellite constellation may be controlled to continuously light up a control channel in the geographic area for the talkgroup. A request to instantiate the talkgroup via the control channel may be received. In response thereto, the satellite constellation may be controlled to continuously light up a traffic channel in the geographic area for the talkgroup. Subsequently, the talkgroup may be determined to be inactive. In response thereto, the satellite constellation may be controlled to stop continuously lighting up the traffic channel in the geographic area while continuing to continuously light up the control channel in the geographic area.

CROSS-REFERENCE TO RELATED APPLICATION

This application is a continuation of U.S. patent application Ser. No.15/016,897 filed on Feb. 5, 2016, which claims the benefit of U.S.Provisional Patent Application No. 62/112,270 filed on Feb. 5, 2015, thedisclosures of each of which are incorporated herein by reference intheir entirety.

TECHNICAL FIELD

The disclosure relates generally to Push-To-Talk (“PTT”) communication,and more specifically to instantiating talkgroups in a PTT communicationsystem.

SUMMARY

According to an implementation of the disclosure, a method may includereceiving information specifying a geographic area for a talkgroup. Themethod may also include receiving information specifying that thetalkgroup is a “warm” talkgroup. Further, the method may includecontrolling a satellite constellation to continuously light up one ormore control channels in the geographic area in response to receivingthe information specifying that the talkgroup is a “warm” talkgroup. Theone or more control channels may be control channels for the talkgroup.In addition, the method may include receiving a request to instantiatethe talkgroup via a control channel of the one or more control channels.Further still, the method may include controlling the satelliteconstellation to continuously light up one or more traffic channels inthe geographic area in response to receiving the request to instantiatethe talkgroup via the control channel. The one or more traffic channelsmay be traffic channels for the talkgroup. Subsequently, the method mayinclude determining that the talkgroup is inactive. The method also mayinclude controlling the satellite constellation to stop continuouslylighting up the one or more traffic channels in the geographic areawhile continuing to continuously light up the one or more controlchannels in the geographic area in response to determining that thetalkgroup is inactive.

Other features of the present disclosure will be apparent in view of thefollowing detailed description of the disclosure and the accompanyingdrawings. Implementations described herein, including theabove-described implementation, may include a method or process, asystem, or computer-readable program code embodied on computer-readablemedia.

BRIEF DESCRIPTION OF THE DRAWINGS

For a more complete understanding of the present disclosure, referencenow is made to the following description taken in connection with theaccompanying drawings.

FIG. 1 is a block diagram of a network for satellite-basedcommunications using one or more communication methods, in accordancewith particular implementations of the present disclosure.

FIG. 2 is a schematic diagram illustrating a satellite-basedimplementation of a push-to-talk system, in accordance with particularimplementations of the present disclosure.

FIG. 3 is a flow chart illustrating a method for establishingcommunication via one or more talkgroups, in accordance with particularimplementations of the present disclosure.

FIG. 4 is a flow chart illustrating a method of maintaining a “warm”talkgroup in a push-to-talk system, in accordance with particularimplementations of the present disclosure.

FIG. 5A is a schematic diagram of a communication device configured toparticipate in a satellite communication system, including, for example,a satellite-based PTT system, in accordance with particularimplementations of the present disclosure; and FIG. 5B is a schematicillustration of a device configured to implement one or processes formanaging communication in a satellite communication system, including,for example, a satellite-based PTT system, in accordance with particularimplementations of the present disclosure.

DETAILED DESCRIPTION

Various implementations set forth in this disclosure are described inrelation to Push-To-Talk (“PTT”) communication protocols implementedthrough a network of cross-linked satellites, but such implementationsare not so limited and may be applied to many other communicationprotocols implemented through many other communication systems. Inparticular implementations set forth herein, satellite-based PTTcommunication may be implemented with one or more so-called “warm”talkgroups defined in particular geographic regions of thesatellite-based PTT network that may be activated more quickly thanother so-called “cold” talkgroups provided by the satellite-based PTTsystem. The definition of the so-called “warm” talkgroups and theircorresponding geographic regions may be performed by a centraladministrator of the PTT network.

Particular implementations of satellite-based PTT networks may permitthe coverage area for a talkgroup to be defined in advance by atalkgroup administrator. A talkgroup administrator may set outboundaries (e.g., using shapes) defining one or more regions of theEarth as the coverage area for the talkgroup within which devices thatare provisioned to participate in the talkgroup will be able to accessthe talkgroup.

In certain satellite-based PTT implementations, a talkgroup may bedefined as a “cold” talkgroup in which the network resources used in theinstantiation of the talkgroup are called into use “from scratch” when acommunication device provisioned to participate in the talkgrouprequests to start a talkgroup session for the talkgroup. A relativelylong period of time may elapse during this “from scratch” talkgroupestablishment while the talkgroup is set up so that it is usablethroughout the defined coverage area for the talkgroup. Customers,however, may desire to reduce this start-up latency, for example, due totheir use models or to keep the differential between terrestrial landmobile radio (“LMR”) network latencies and the satellite-based PTTnetwork latencies more in line with each other.

Satellite-based PTT talkgroup sessions may be established by allocatingstatic/bearer or traffic channels within the satellite beams thatprovide coverage of the defined coverage area for the talkgroup. Inparticular implementations, within each beam that provides coverage ofthe defined coverage area for a talkgroup, a control channel and atraffic channel (described in more detail below) may be active to enablecommunication devices provisioned to participate in the talkgroup to beable to participate in a talkgroup session, for example. For a so-called“cold talkgroup,” when a communication device provisioned to participatein the talkgroup requests that a talkgroup session be initiated, controlchannels typically will be allocated within the beams that providecoverage of the defined coverage area for the talkgroup in response tothe request to initiate the talkgroup session. These control channelsthen are used to signal the setup of the traffic channels that carry theactual communications of the talkgroup.

This process of setting up the control channels for the talkgroup maytake about half of the nominal time required to fully instantiate thetalkgroup (e.g., 1 second of a total 2 seconds of latency to initiate atalkgroup session). Particular implementations described herein mayeliminate or significantly reduce the latency associated with setting upthe control channels (e.g., 1 second) by implementing a so-called “warm”talkgroup for which the control channels may be maintained (e.g.,permanently or for extended durations of time like days, weeks, ormonths) for the coverage area defined for the talkgroup. In this manner,when a talkgroup session is initiated for a “warm” talkgroup by a memberdevice, the control channel already are established and only the trafficchannels need be allocated anew for the talkgroup session. Consequently,the total latency required to instantiate the talkgroup may be reducedby about one half (e.g., 1 second).

In contrast to the “cold” talkgroups and “warm” talkgroups describedabove, other implementations of satellite-based PTT communications mayutilize so-called “hot” talkgroups. In “hot” talkgroups, both thecontrol channels and the traffic channels used for communication withinthe talkgroup may be maintained (e.g., permanently or for extendedperiods of time like days, weeks, or months), regardless of whetherdevices are using the talkgroup. These “hot” talkgroups may eliminate(or significantly reduce) the latency associated with instantiating“cold” talkgroups, but may use power and resources less efficiently, forexample, by maintaining one or more unused traffic channels andpreventing such traffic channels from being dynamically used for otherpurposes.

Certain satellite-based PTT implementations may provide a combination of“cold,” “warm,” and “hot” talkgroups. For example, in someimplementations, an administrator may maintain a plurality oftalkgroups. Some of the talkgroups may be “cold” talkgroups, some of thetalkgroups may be “warm” talkgroups, and/or some of the talkgroups maybe “hot” talkgroups. Talkgroups deemed to have relatively highimportance may be defined as “warm” talkgroups and talkgroups deemed ashaving relatively lower importance may be defined as “cold” talkgroups.For example, a talkgroup designated for emergency communication may bedefined as a “warm” talkgroup to enable more rapid communication andresponse.

As described above, “cold” talkgroups may implement a relativelyefficient approach to resource utilization. When a device wishes toinitiate a talkgroup session for a “cold” talkgroup, the device mayrequest resources from the network to instantiate the talkgroup, and thenetwork may instantiate the talkgroup according to a two-step process.First, control channels may be set up within the beams that cover thedefined coverage area of the talkgroup. Second, the control channels maybe used by the devices within the defined coverage area for thetalkgroup to access the traffic channel(s) for the talkgroup within theone or more beams that cover the coverage area for the talkgroup. Insuch implementations, the “cold” talkgroups may be defined for apredefined and static geographic region (e.g., the entire geographicregion is “lit up” when the talkgroup is instantiated). For example, thecoverage area for such a “cold” talkgroup may be defined to include thecontinental United States and Europe. To initiate a talkgroup sessionfor the talkgroup, a user in the continental United States may press aPTT button on a communication device provisioned to participate in thetalkgroup or otherwise interact with the communication device to requestthe initiation of a talkgroup session. In response, the satellite-basedPTT network may setup control channels in the beams that cover thecontinental United States and Europe as part of the talkgroup set upprocess. Communication devices within the defined coverage area andprovisioned to participate in the talkgroup then may use the controlchannels to access traffic channels allocated for the talkgroup.

As noted above, particular satellite-based PTT implementations describedherein may offer “warm” talkgroups. In some such systems providing“warm” talkgroups, at least one channel per beam covering the coveragearea defined for the talkgroup may be allocated permanently (or for anextended period of time) as a control channel for a “warm” talkgroup,and that control channel may be active all of the time and available foruse. Meanwhile, no traffic channels may be allocated for the talkgroupwithin the defined coverage area for the talkgroup until the controlchannel(s) signal that a talkgroup session has been initiated for the“warm” talkgroup. Consequently, instead of having to set up both thecontrol channel(s) and the traffic channel(s) (which may result inrelatively high latency but relatively efficient resource utilization)or actively maintain both the control channel(s) and the trafficchannel(s) (which may result in relatively low latency but relativelyinefficient resource utilization), “warm” talkgroups may present amiddle ground between “cold” talkgroups and “hot” talkgroups that mayreduce latency while still allowing for relatively efficient resourceutilization. For example, the channels used as traffic channels for the“warm” talkgroup may be shared with other talkgroups when the “warm”talkgroup is not active.

In some satellite-based PTT systems, “warm” talkgroups may be definedfor particular defined coverage areas (e.g., even if the satellites thatprovide coverage to the defined coverage areas change due to theirorbits) such that control channel(s) corresponding to the talkgroups arecontinuously maintained (e.g., permanently or for extended periods oftimes like days, weeks, or months) throughout the coverage areas for the“warm” talkgroups. In a satellite-based PTT implementation in which a“warm” talkgroup is supported by a non-geostationary satelliteconstellation, for example, like a low-Earth orbit (LEO satelliteconstellation) the satellites may continuously move relative to theEarth such that coverage is provided to the coverage area by differentsatellites as the satellites orbit the Earth. Consequently, when anindividual satellite moves into range to cover all or some portion ofthe coverage area defined for the talkgroup, the satellite may provide acontrol channel for the talkgroup within each of the satellite's beamsthat covers the coverage area for the talkgroup. The satellite maycontinuously maintain these control channels until the satellite movesout of range of the coverage area defined for the talkgroup. At thatpoint, the satellite may deactivate the control channels while one ormore other satellites move into place and provide the control channelsfor the talkgroup within the defined coverage area for the talkgroup.

In certain implementations, control channel(s) set up for a individual“warm” talkgroup may by unique to the “warm” talkgroup. For example,such control channel(s) may carry only information relevant to the“warm” talkgroup and may not carry information about other talkgroupsand/or devices that are not provisioned to communicate in the “warm”talkgroup. Consequently, this may reduce the volume of informationcarried by the control channel(s) and may further reduce latencyassociated with the “warm” talkgroup.

As described above, an administrator may define the parameters of a“warm” talkgroup. For example, the administrator may define one or moreof the geographic area covered by the “warm” talkgroup, the devicesprovisioned to use the “warm” talkgroup, which talkgroups are “warm”talkgroups, and triggering events that may cause the “warm” talkgroup tobecome a “cold” talkgroup or a “hot” talkgroup. Moreover, theadministrator may dynamically change these defined parameters at anytime. For example, the administrator may define a talkgroup on aseasonal basis, such that the talkgroup is “warm” at times of the yearwhen the geographic area defined for the talkgroup is more-frequentlyutilized and “cold” at times of the year when the geographic areadefined for the talkgroup is less-frequently utilized.

In some implementations, “warm” talkgroups may be defined for geographicareas with a relatively high density of devices and/or a high amount oftalkgroup utilization (e.g., the continental United States) and “cold”talkgroups may be defined for geographic areas with a relatively lowdensity of devices and/or a low amount of talkgroup utilization (e.g.,over the Atlantic Ocean) or vice versa.

In certain implementations, a talkgroup may include combinations of“cold,” “warm,” and/or “hot” components. For example, the coverage areafor a talkgroup may be defined to include a large geographic region ormultiple non-contiguous geographic regions, and the talkgroup may bedefined as a “cold” talkgroup in a first portion of the coverage areaand a “warm” talkgroup in a second portion of the coverage area. In suchan implementation, the control channel(s) covering the second portion ofthe coverage area may be maintained (e.g., permanently or for extendedperiods of time) when the talkgroup is inactive, but the controlchannel(s) covering the first portion of the coverage area may be torndown when the talkgroup is inactive. Accordingly, latency associatedwith instantiating the talkgroup may be higher for devices disposed inthe first region than for devices disposed in the second region.Nevertheless, this may further reduce resource utilization associatedwith regions where latency is less of a concern.

Referring now to FIG. 1, a network 100 may facilitate communicationbetween communication devices using one or more communication methods.Specifically, FIG. 1 illustrates a block diagram of a network forsatellite-based communication using one or more communication methods.Network 100 may comprise a plurality of satellites 110, each of whichmay permit the exchange of information and services among devices thatare connected via satellites 110. Network 100 may also comprise aplurality of satellite links 115 (e.g., Earth-based satellite dishes,vehicle-based satellite dishes, high-power transmitters and receivers,antennas, Earth terminals, teleports) that may be configured tocommunicate with the one or more satellites 110 and relay data back andforth with the one or more satellites 110. In certain implementations,network 100 may comprise a plurality of cross-linked satellites 110 thateffectively form a network between satellites 110 across whichcommunications can be transferred. In other implementations, forexample, network 100 may comprise one or more satellites 110 and eachsuch satellite 110 may not directly connect to another satellite 110. Insuch other implementations, each satellite 110 may have a “bent pipe”architecture in which satellites 110 may only connect indirectly withone another through terrestrial-based systems, for example.

In addition, network 100 may comprise one or more management centers 130(e.g., a Network Operations Center (“NOC”) and/or a gateway forinterfacing the satellite-based portion of network 100 to one or moreterrestrial-based portions of network 100) configured to connect to atleast one of the plurality of satellites 110. A management center 130may comprise one or more locations (e.g., devices) that may monitor,control, or manage network 100. Each management center 130 may manageand monitor one or more satellites 110. For example, management center130 may control movement or positioning of a satellite 110, may receiveand monitor communications between a satellite 110 and other devices, ormay determine when satellite 110 needs maintenance. In someimplementations, a dedicated management center 130 may be establishedfor each satellite 110. Alternatively, in some other implementations, amanagement center 130 may manage and monitor a plurality of satellites110. In such implementations, management center 130 may connect directlywith only one satellite 110 that is within range for directcommunication with management center 130 via satellite link 115, orpossibly a few satellites 110 that are within range of satellite link115, and management center 130 may indirectly manage and control othersatellites 110 in network 100 through cross-linked communicationsbetween the satellite (or satellites) 110 within range of satellite link115 and satellites 110 outside of the range for direct communicationwith management center 130 via satellite link 115.

In some implementations, one or more satellites 110 may maintain ageostationary orbit, and management center 130 may always directlycommunicate, via satellite link 115, with the same satellite 110 thatalways remains in a geostationary position within range for directcommunication with management center 130 via satellite link 115, forexample. In other implementations, one or more satellites 110 may notmaintain a geostationary orbit, and management center 130 may directlycommunicate with different satellites 110 at different times based onwhich satellite 110 or satellites 110 are within range for directcommunication with management center 130 via satellite link 115 at anygiven time. Such satellites may be Low Earth Orbiting (“LEO”)satellites, for example.

Management center 130 may be connected to one or more clouds 140, whichmay be public clouds, private clouds, or community clouds. Each cloud140 may permit the exchange of information and services among devices(e.g., management center 130) that are connected to such clouds 140. Incertain implementations, cloud 140 may be a wide area network, such asthe Internet. In some implementations, cloud 140 may be a local areanetwork, such as an intranet. Further, cloud 140 may be a closed,private network in certain implementations, and cloud 140 may be an opennetwork in other implementations. Cloud 140 may facilitate thetransmission of information among users or devices (e.g., managementcenter 130, devices 120) that are connected to cloud 140 through anynumber of communication means, such as wireless transmission ofinformation or wired transmission of information, for example.Management center 130 may integrate signals or data from satellites 110with terrestrial systems, such as cellular networks, the public switchedtelephone network (“PSTN”), and/or the Internet via cloud 140, forexample.

One or more devices 120 may connect with management center 130. Suchdevices 120 and management center 130 may transmit data therebetween.Devices 120 may include, for example, one or more general purposecomputing devices, specialized computing devices, mainframe devices,wired devices, wireless devices, monitoring devices, infrastructuredevices, other devices configured to provide information to serviceproviders and users, telephones, mobile phones, computer devices, tabletcomputers, personal digital assistants, routers, switches, and any othersuitable communication device. In certain implementations, for example,a device 120 connected with management center 130 may function as amanagement center and may mange a plurality of talkgroups (described inmore detail below) assigned to a plurality of devices, such ascommunication devices 150 (described below in more detail), ororganizations. In such implementations, the device 120 may establish,for example, connection orders for such talkgroups, priority settingsfor such talkgroups, home settings for such talkgroups, securitysettings or keys for such talkgroups, or other protocols for talkgroups.

Network 100 may include a plurality of gateways 135. Gateways 135 mayfunction similarly to management center 130, except that gateways 135may not have rights to control satellites 110 or responsibilities tomanage satellites 110. In certain implementations, gateways 135 maycommunicate with satellites 110 via satellite links 115. In otherimplementations, gateways 135 may utilize other methods requiring lessinfrastructure, such as low power antennas, transmitters, or receivers,to communicate with satellites 110. For example, gateways 135 may serveas bridges between satellites 110, cloud 140, and devices 120 and maypermit the free (or controlled) flow of data therebetween.

Network 100 may include a plurality of communication devices 150.Similar to devices 120, communication devices 150 may include, forexample, one or more general purpose computing devices, specializedcomputing devices, mainframe devices, wired devices, wireless devices,monitoring devices, infrastructure devices, other devices configured toprovide information to service providers and users, telephones, mobilephones, computer devices, tablet computers, personal digital assistants,routers, switches, and any other suitable communication device.Communication devices 150 may be configured to collect data from orprovide data to one or more data sources (e.g., servers, networks,interfaces, other devices). For example communication devices 150 maycollect information from network 100, management center 130, satellitelink 115, satellites 110, and other devices connected to satellites 110,such as other communication devices 150. By collecting this information,communication devices 150 may perform one or more tasks associated withtalkgroups, as discussed in more detail below, and other communicationmethods.

More particularly, communication devices 150 may establish directcommunication with satellites 110 orbiting above their terrestrialpositions. Accordingly, communication devices 150 may utilize satellites110 to establish communication with other communication devices 150,with management center 130, with cloud 140, with devices 120, withgateway 135, and with any other suitable device or system. Communicationdevices 150 may include features similar to those of devices 120 and maysimilarly communicate with management centers 130 and gateways 135 incertain implementations.

Network 100 may be configured to facilitate PTT communication. PTTcommunication is a method of communicating that, in someimplementations, may use half-duplex communication lines in which acommunication device, such as a communication device 150, switchesbetween a dedicated transmission mode and a dedicated reception mode,for example, for the purposes of communicating with one or more othercommunication devices that collectively may be referred to as atalkgroup. In some implementations of PTT communication, thecommunication device may be in the dedicated reception mode by defaultand may switch to the dedicated transmission mode only while a “talk”button is pushed or otherwise activated. In other implementations of PTTcommunication, the communication device may switch from the dedicatedreception mode to the dedicated transmission mode in response to a firsttrigger, such as the selection of the dedicated transmission mode on thecommunication device, the detection of a particular sound (e.g., auser's voice, a particular word or command, a particular tone), or thereceipt of any other instruction or command to switch to the dedicatedtransmission mode, and the communication device may remain in thededicated transmission mode until a second trigger occurs and thecommunication device switches to the dedicated reception mode inresponse thereto. For example, the second trigger may include theselection of the dedicated reception mode on the communication device,the lapse of a particular period of time (e.g., 30 seconds, 1 minute, 5minutes, 30 minutes, 1 hour) in the dedicated transmission mode, theabsence of a particular sound (e.g., the user's voice), the detection ofa particular sound (e.g., a particular word or command, a particulartone), or the receipt of any other instruction or command to end thededicated transmission mode or to switch to the dedicated receptionmode. In some instances, when a communication device is in the dedicatedtransmission mode, the device may be said to “have the floor” of thetalkgroup.

Throughout this disclosure, PTT communications and communications moregenerally are described often in the context of voice communications.However, the systems and techniques described herein are not limited tocommunications involving voice. Rather, the systems and techniquesdescribed herein, and particularly the “warm” talkgroup functionality,are more generally applicable to all forms of communication, includingdata communication. In fact, in some implementations, the communicationdevices engaging in PTT communications may not be user devices such ashandsets and the like, but instead may be machine-to-machine (“M2M”) orother data communication devices that, for example, generally may bereferred to as facilitating the “Internet of Things” (“IoT”). Forinstance, the communication devices may interface with sensors or othertypes of data processing and/or generating devices and may be configuredto participate in PTT communication sessions, for example, involving oneor more other communication devices, to share data. In suchimplementations, the communication devices still may exchange data withother communication devices within a talkgroup using PTT techniques, andthe communication devices still may employ the “warm” talkgrouptechniques described herein. Furthermore, while the term “PTT” or“push-to-talk” may suggest that something (e.g., a button) must be“pushed” (and, in some cases, held) in order for a communication deviceto “take the floor” or otherwise communicate in a dedicated transmissionmode in a talkgroup, that is not necessarily the case. As describedherein, there are various other mechanisms through which communicationdevices can “take the floor” or otherwise communicate in a dedicatedtransmission mode in a talkgroup, particularly in implementations wherethe communication devices are not user devices but instead are M2M orother data communication devices.

PTT communication may facilitate communication between a plurality ofdevices, such as communication devices 150, by establishingcommunication protocols that govern which communication device 150 “hasthe floor” (e.g., is set to a dedicated transmission mode) and whichcommunication device or devices 150 are listening (e.g., are set to thededicated reception mode). Consequently, PTT communication mayefficiently allocate communication roles (e.g., either being in adedicated transmission mode or being in a dedicated reception mode)among a group of communication devices 150.

In some implementations of PTT communication, communication systemsother than or in addition to half-duplex communication lines may beused. For example, some implementations of PTT communication may utilizetwo-way (or full) duplex communication lines in which a plurality ofcommunication devices 150 may simultaneously be in transmission modes.In such alternative implementations, for example, users of a pluralityof communication devices 150 may speak simultaneously and may all beheard by users of other communication devices 150 connected with thespeaking users.

In PTT communication, communication may occur via one or more trafficchannels. A traffic channel may correspond to an electromagnetic wave,such as a radio wave, of a particular frequency. A plurality ofcommunication devices may connect to one or more traffic channel. Inparticular, a communication device set to the dedicated transmissionmode and connected to a particular traffic channel may transmit acommunication over the traffic channel, e.g., by transmitting anelectromagnetic wave at the frequency corresponding to the trafficchannel, to communication devices set to the dedicated reception mode ornetwork nodes (e.g., a satellite 110) connected to the traffic channel.For example, a user may speak into a first communication device set tothe dedicated transmission mode and connected to the traffic channel;the first communication device may encode the user's message in a radiosignal and transmit the radio signal over the traffic channel (e.g., toa satellite); one or more second communication devices set to thededicated reception mode and connected to the traffic channel mayreceive the radio signal (e.g., retransmitted by the satellite),including the encoded message, over the traffic channel; and the one ormore second communication devices may output the user's message in theuser's voice to the respective users of the one or more secondcommunication devices. In this manner, a communication device set to thededicated transmission mode and connected to the traffic channel maytransmit a communication (e.g., a voice communication, Morse code, adata packet) simultaneously to all (or some subset of all) othercommunication devices set to the dedicated reception mode and connectedto the traffic channel. As described below in more detail, PTTcommunication may utilize talkgroups, which function similar to thetraffic channels described above but allow communication betweencommunication devices set to a plurality of different traffic channels.

In some implementations of PTT communication, only one communicationdevice per traffic channel may be set to the dedicated transmission modeat a time. Consequently, if a communication device connected to atraffic channel is set to the dedicated transmission mode, the othercommunication devices connected to the traffic channel may not switch tothe dedicated transmission mode until the communication device set tothe dedicated transmission mode is switched to the dedicated receptionmode or otherwise deactivated, even if a first trigger for switching oneof the other communication devices to the dedicated transmission modeoccurs. For example, if pushing a particular button on a particularcommunication device is the first trigger for switching the particularcommunication device to the dedicated transmission mode, in such animplementation, pushing the particular button may not switch theparticular communication device to the dedicated transmission mode untilafter the communication device currently set to the dedicatedtransmission mode is switched to the dedicated reception mode orotherwise deactivated. In some implementations, when a first trigger forswitching one of the other communication devices to the dedicatedtransmission mode occurs, the first trigger may also serve as a secondtrigger for switching the communication device currently in thededicated transmission mode to the dedicated reception mode, which mayallow one of the other communication devices to switch to the dedicatedtransmission mode.

PTT communication also may utilize a control channel that may carryinformation about each of a plurality of traffic channels. The controlchannel may correspond to an electromagnetic wave, such as a radio wave,of a dedicated frequency. The control channel may provide a data streamincluding, for example, information about one or more of the availabletraffic channels or about the traffic channels in aggregate. Suchinformation may include, for example, the number of available trafficchannels and the frequencies of available traffic channels.Alternatively or additionally, the data stream may include informationabout communication devices associated with the one or more availabletraffic channels including, for example, the number of communicationdevices connected to or waiting for each traffic channel, the types ofcommunication devices connected to or waiting for each traffic channel,the length of time one or more communication devices have been connectedto each traffic channel, whether a communication device connected to aparticular traffic channel is set to the dedicated transmission mode,which communication device is currently set in a dedicated transmissionmode on a particular traffic channel, the length of time a communicationdevice has been set in a dedicated transmission mode on a particulartraffic channel, the length of time a particular traffic channel hasbeen active (e.g., an aggregate length of time that one or morecommunication devices have been set in a dedicated transmission mode ona particular traffic channel), which communication device is currentlyset in a dedicated reception mode on a particular traffic channel,whether each traffic channel is available, and other information aboutthe communication devices connected to the traffic channels.

In implementations of PTT communication utilizing talkgroups, thecontrol channel data stream may include information including, forexample, information identifying whether a traffic channel is assignedto a talkgroup, information identifying traffic channels assigned toparticular talkgroups, and other information about the traffic channelsand any talkgroups to which traffic channels are assigned. Suchinformation may allow communication devices to connect with or remainconnected to talkgroups as the frequencies or traffic channelsassociated with the talkgroups are reallocated and as the communicationdevices move relative to satellites 110 (or as satellites 110 moverelative to the communication devices) and the respective beams thereof,which may, for example, result in handoffs being made between beams,satellites, etc.

As described below in more detail, talkgroups may be characterized aseither active talkgroups (sometimes referred to as “live” talkgroups) orinactive talkgroups (sometimes referred to as “dead” talkgroups). Forexample, active talkgroups may be talkgroups on which activecommunication is currently occurring (e.g., a user is currently speakinginto a communication device connected to a talkgroup and thecommunication device is transmitting the spoken audio in a dedicatedtransmission mode) or on which active communication has occurred withina particular period of time. Similarly, inactive talkgroups may betalkgroups on which active communication is not currently occurring(e.g., no communication devices are connected to the talkgroup andtransmitting in a dedicated transmission mode) or on which activecommunication has not occurred within a particular period of time.

In some instances, a talkgroup may be determined to be active even ifactive communication (e.g., speaking, data transmission) is notcurrently occurring (or has not occurred within the particular period oftime) within the talkgroup. For example, communication devices maydetermine whether a talkgroup is active or inactive based on informationfrom the control channel indicating whether one or more traffic channelsare currently allocated to the talkgroup (or have been allocated to thetalkgroup) within the particular period of time, rather than determiningwhether active communication is actually occurring (or has occurredwithin the particular period of time). For example, if control channel 0provides information indicating that traffic channel 1 is currentlyallocated to talkgroup A or has been allocated to talkgroup A within aparticular period of time (e.g., within the last 10 seconds), then acommunication device 150 listening to control channel 0 may determinethat talkgroup A is an active talkgroup. Alternatively, if controlchannel 0 provides information indicating that no traffic channels arecurrently allocated to talkgroup A or that no traffic channels have beenallocated to talkgroup A within the particular period of time, then acommunication device 150 listening to control channel 0 may determinethat talkgroup A is an inactive talkgroup.

In some implementations, traffic channels may be allocated to atalkgroup in response to a request from a communication deviceprovisioned to participate in the talkgroup. For example, if thetalkgroup is inactive, no traffic channels may be currently allocated tothe talkgroup. In response to a communication device that is provisionedto participate in the talkgroup requesting to participate in thededicated transmission mode, one or more traffic channels may beallocated to the talkgroup to enable communications over the talkgroup.Thereafter, traffic channel(s) may be maintained for the talkgroup untilno devices provisioned to participate in the talkgroup have participatedin the talkgroup in the dedicated transmission mode for more than somedefined threshold period of time. After the defined threshold period oftime elapses with no device provisioned to participate in the talkgrouphaving participated in the talkgroup in the dedicated transmission mode,the traffic channel(s) allocated to the talkgroup may be torn down andthe talkgroup may transition back to an inactive status.

In some implementations, data transmitted in the control channel mayexplicitly define whether a talkgroup is active or inactive. Forexample, in some implementations, a centralized entity (e.g., managementcenter 130) may determine whether a talkgroup is active or inactive(e.g., based on whether active communication is occurring or hasoccurred within a defined period of time within the talkgroup) andtransmit an indication of whether the talkgroup is active or inactivewithin the control channel.

A plurality of talkgroups may be available to particular communicationdevices or users. For example, available talkgroups for particularcommunication devices or users may be provisioned by management center130, gateway 135, or a device 120 based on the communication devices' orusers' affiliation with an organization. As an example, one set ofavailable talkgroups may be provisioned for users or devices affiliatedwith a particular branch or division of the U.S. military, while anotherset of available talkgroups may be provisioned for a petroleumprospecting company, and still another set of available talkgroups maybe provisioned for employees or aircraft of an airline. Each set ofavailable talkgroups may include a plurality of talkgroups that may onlybe accessible (e.g., available) to devices or users associated with theorganization to which the respective set of available talkgroups wasprovisioned. Such available talkgroups may, however, utilize the samebeams and/or traffic channels, but utilization of the beams and/ortraffic channels may be dynamically allocated such that each individualset of available talkgroups remains accessible only to devices or usersassociated with the organization to which the talkgroups wereprovisioned. Further, in some implementations, each set of availabletalkgroups may be affiliated with one or more control channels thatcarry information about such available talkgroups. In otherimplementations, certain talkgroups may only be available using aparticular access code, for example.

A plurality of communication devices may connect to a control channel,and the data transmitted in the control channel may enable eachcommunication device of the plurality of communication devices (or eachuser thereof) to select a traffic channel to which such communicationdevice may connect and to determine whether such communication devicemay be switched to the dedicated transmission mode at a particularinstant in time. In some implementations, the control channel may evenprovide commands or assignments for particular communication devices toconnect with particular traffic channels. Further, the control channelor a similar channel may be used for establishing a connection between afirst set of one or more communication devices and a second set of oneor more communication devices through the Internet or another datanetwork.

In some implementations, communication devices may continuously monitorthe control channel. In other implementations, communication devices mayselectively or periodically access the control channel, such as when asetting is changed or requested to be changed in the communicationdevice (e.g., changing or requesting to change between a dedicatedtransmission mode and a dedicated reception mode, changing or requestingto change between talk groups), when the communication device isactivated or removed from a sleep or hibernation state, or atpredetermined or specified intervals of time. In some implementations,the data in the control channel may be continuously transmitted (e.g.,broadcast) to the connected communication devices. In otherimplementations, the data in the control channel may be periodically orintermittently transmitted (e.g., broadcast) to the connectedcommunication devices. Additionally or alternatively, the data in thecontrol channel may be transmitted (e.g., broadcast) to the connectedcommunication devices in response to the occurrence of or when certainevents occur, such as a new communication device connecting to thecontrol channel or when a communication device is activated or switchesbetween the reception mode and the transmission mode, for example.

In satellite-based implementations of PTT communication systems,satellite 110 may generate one or more beams or spot beams that enablethe satellite to transmit and/or receive one or more different datasignals within each beam. Such beam(s) may create a footprint spanning aparticular geographic region of the Earth. The footprint may be based onthe characteristics of a satellite 110's antenna, such as the antenna'sgain pattern, transmission power, transmit and/or receive frequencies,and the efficiency or quality of the antenna, for example. In someimplementations, the radius of the particular geographic region withinthe footprint of a particular beam may be about 400 km. In otherimplementations, the radius of the particular region may besubstantially less than or greater than 400 km based on factors such asthe transmission power associated with the particular beam and sourcesof interference (e.g., mountains, trees, buildings, electromagneticradiation sources). In some implementations, each satellite 110 mayprovide a plurality of beams, and each such beam may be directed to adifferent geographic region. Certain satellites 110 may move relative tothe Earth over time, such that the geographic regions within thefootprints of the satellites' 110 beams also change over time. Othersatellites 110 may be geostationary, and the geographic regions withinthe footprints of the satellites' 110 beams may remain fixed in time orat least fixed for periods of time. Moreover, some satellites 110 may beconfigured to direct one or more beams to cover different geographicregions or to change power characteristics, such that the size of thegeographic regions within the footprint(s) of the beam(s) may change.

Each beam may include a plurality of carriers (e.g., channels,frequencies), for example. In some implementations, frequencies may beassigned within the full spectrum of the beam, and such frequencies maybe shared by communication devices within the footprint of the beam. Inother implementations, frequencies may be assigned within only a portionof the full spectrum of the beam. Each beam may include one or morecontrol channels (e.g., control channel 0) and a plurality of trafficchannels (e.g., traffic channels 1, 2, 3, and 4). Accordingly, the oneor more control channels and the plurality of traffic channels includedin a particular beam may be available to the communication deviceswithin the footprint of the particular beam. In some instances, however,interference sources may prevent some communication devices within thefootprint of the particular beam from accessing the one or more controlchannels and/or the plurality of traffic channels in the particularbeam.

In some implementations, beams from different satellites may createfootprints that overlap with one another. In such cases, eachcommunication device in such an overlapping region may only receiveinformation from one control channel at a time. Consequently, thecommunication devices may be configured to select between the controlchannels associated with overlapping beams based on certain criteria.Such criteria may include, for example, one or more of the relativestrength of the signal received from each beam (e.g., there may be apreference to select the control channel corresponding to the beam witha higher strength), whether the strength of the control channelcurrently being monitored is less than or equal to a particular signallevel (e.g., there may be a preference to stay connected with thecurrent beam until the signal strength of the beam becomes too low), anda determination of whether the communication device is currentlycommunicating with other communication devices within the footprint ofone of the beams (e.g., there may be a preference to stay connected withthe current beam to maintain uninterrupted communication with the othercommunication devices).

In particular implementations, talkgroups may be associated withparticular coverage areas. For example, a talkgroup provisioned to acity fire department may be available only in a coverage area that iscoterminous with the city's boundaries. In another example, a particulartalkgroup may only be available in a geographic area covered by aparticular beam from a particular satellite. In these particularimplementations, for example, communication devices may only participatein a particular talkgroup when such communication devices are within thecoverage area of the particular talkgroup.

FIG. 2 shows a schematic of one example of a satellite-basedimplementation of a PTT system. As shown in FIG. 2, each ofcommunication devices 150 may monitor control channel 0. Somecommunication devices 150, such as communication devices 150 a and 150b, may be set to transmit or receive communications via trafficchannel 1. Other communication devices 150, such as communication device150 c, may be set to transmit or receive communications via trafficchannel 2. Still other communication devices 150, such as communicationdevice 150 d, may be set to transmit or receive communications viatraffic channel 3. Additional communication devices 150, such ascommunication devices 150 e and 150 f, may be set to transmit or receivecommunications via traffic channel 4. Certain communication devices 150,such as communication device 150 g, may not be set to transmit orreceive communications via any of traffic channels 1-4. Furthermore, thesettings of communication devices 150 a-g may be changed, such that oneor more of communication devices 150 a-g may be reset to transmit orreceive communications via different ones of traffic channels 1-4 thanthose shown in FIG. 2.

PTT communication systems, such as network 100, may utilize a trunkedradio system including a plurality of talkgroups. The trunking functionmay be implemented by a device 120 or by management center 130, forexample. In some implementations, a talkgroup may be implementedgenerally using a communication channel within a trunked radio systemthat may function the same as or similarly to a traffic channel asdescribed above; however, in some implementations, unlike a trafficchannel assigned to a particular radio frequency, a particular talkgroupmay utilize different radio frequencies at different times. A trunkedradio system may include a control channel and a limited number oftraffic channels. Communication devices using the trunked radio systemmay monitor the control channel to determine available traffic channels(e.g., traffic channels without current communication activity such asconnected devices or active communication transmissions from devices setin a dedicated transmission mode). When a communication device is set toa particular talkgroup, the communication device may either assign anavailable traffic channel to the particular talkgroup or identify atraffic channel currently assigned to the particular talkgroup.Thereafter, the communication device may begin transmitting or listeningon the traffic channel assigned to the talkgroup set on thecommunication device.

Referring to FIG. 2, communication devices 150 a and 150 b may both beparticipating in the same talkgroup, for example. Moreover, each ofcommunication devices 150 a-150 g may be provisioned to participate in aplurality of talkgroups, such that communication devices 150 a-150 g mayswitch back and forth between talkgroups. For example, communicationdevice 150 a may be provisioned to participate in a talkgroup currentlyactive on traffic channel 4 and, consequently, may switch into thattalkgroup to communicate with communication devices 150 e and 150 f.

An example of a process of establishing communication via a talkgroup isshown in FIG. 3. In S301, a communication device may be set to aparticular talkgroup, such as a talkgroup A, for example. Thereafter, inS305 the communication device may determine which traffic channel to useto connect the communication device to talkgroup A. For example, thecommunication device may analyze the information from a control channel,such as control channel 0, to determine if a traffic channel already hasbeen assigned to talkgroup A (e.g., because other devices are currentlyconnected to talkgroup A or communicating in talkgroup A). If a trafficchannel already has been assigned to talkgroup A, the communicationdevice may use the information from control channel 0 to determine whichtraffic channel is currently associated with talkgroup A.

If a traffic channel has not already been assigned to talkgroup A, forexample, because talkgroup A is not currently instantiated, thecommunication device may request that talkgroup A be instantiated and/orthat a traffic channel be assigned to talkgroup A. In such a scenario(e.g., in the case of a “cold” talkgroup), there may not be an existingcontrol channel allocated to provide information about talkgroup A.Therefore, in response to the request from the communication device, oneor more control channels as well as one or more traffic channels for thetalkgroup may be allocated within the beam(s) providing coverage of thecoverage area for the talkgroup, and information about the assignedtraffic channel(s) for talkgroup A may be provided via the controlchannel(s). Alternatively, if an existing control channel has beenallocated to provide information about talkgroup A even though talkgroupA is not currently instantiated (e.g., in the case of a “warm”talkgroup), the communication device may transmit the request via thecontrol channel or another channel and information about the trafficchannel(s) allocated for talkgroup A may be transmitted to thecommunication device within the control channel.

After determining which traffic channel is associated with talkgroup Ain S305, the communication device may connect to the assigned trafficchannel in S309 and may begin transmitting or listening within talkgroupA.

Management center 130, gateway 135, or a device 120 may be responsiblefor associating a particular traffic channel with talkgroup A andtransmitting this information out through control channel 0 to bereceived by communication devices 150, for example. Consequently, thisinformation may be added to the control channel and the control channelmay include information identifying the particular traffic channelassigned to talkgroup A. This information may be used by othercommunication devices when such communication devices perform S305 afterbeing set to talkgroup A in S301.

Communication devices may disconnect from a talkgroup by switching toanother talkgroup, entering a sleep or hibernation mode, or beingdeactivated, for example. Accordingly, once all of the devicespreviously connected to a particular talkgroup disconnect from theparticular talkgroup or when no communication is currently beingperformed via the particular talkgroup (e.g., there are no devicestransmitting in a dedicated transmission mode via the particulartalkgroup or no devices have transmitted in a dedicated transmissionmode via the particular talkgroup for a defined period of time), thetraffic channel assigned to the particular talkgroup may becomeavailable for use by other talkgroups or for other communicationmethods. In some implementations, there may be a predetermined orselectable delay period between the time when all of the devices havedisconnected from the talkgroup or the time when communication via thetalkgroup has terminated and the time when the traffic channel assignedto the particular talkgroup becomes available for use by othertalkgroups (e.g., 1 second, 5 seconds, 1 minute, 5 minutes). When adelay period exists, control channel 0 may also wait for the delayperiod before providing information that the traffic channel previouslyassigned to the particular talkgroup is available and that theparticular talkgroup currently is not established.

In the manner described above, traffic channels may be dynamicallyallocated among talkgroups to efficiently reduce instances in whichtraffic channels are unused and to reduce the duration of such disuse.Further, certain users of network 100 may desire more securecommunications. By giving these users access to particular talkgroupsthat frequently cycle through different traffic channels, these usersmay be able to communicate more securely than would otherwise bepossible over a static traffic channel.

Particular implementations of a satellite-based PTT communication systemoffering a “warm” talkgroup feature now are disclosed in more detailwith respect to FIG. 4.

FIG. 4 is a flow chart illustrating a method of providing a “warm”talkgroup in a satellite-based PTT system, in accordance with particularimplementations of the present disclosure.

In particular implementations, the method of providing a “warm”talkgroup in a satellite-based PTT system may be implemented withinnetwork 100 where it is desirable to reduce the latency associated withinstantiating a particular talkgroup for communication between aplurality of communication devices. Such communications may be, forexample, emergency broadcasts, warnings, transmissions of critical dataor software, monitored parameters, or any other information that may bedesirable to communicate to the particular group of devices rapidly.

In S402, one or more geographic areas are selected as the coverage areafor a talkgroup, for example, by an administrator at a management center130 (e.g., an operations hub). One or more communication devices 150 maybe provisioned to communicate on network 100 using the talkgroup, forexample. The administrator may, for example, use a device 120 connectedto management center 130 to select the geographic area(s). Each deviceprovisioned to participate within the particular talkgroup may accessthe talkgroup when such device is disposed within the particulargeographic area defined in S402.

In S404, the administrator may define the particular talkgroup as a“warm” talkgroup. For example, the administrator may determine thatthere is a need for reduced latency associated with instantiation of theparticular talkgroup and, as a result, may determine that the particulartalkgroup should be maintained as a “warm” talkgroup. In certainimplementations, S404 may be performed prior to S402, for example, suchthat the particular talkgroup is defined as a “warm” talkgroup prior todefining the geographic area covered by the talkgroup.

In S406, device 120 may inform satellites 110, via network 100, of thecoverage area for the particular talkgroup and that the particulartalkgroup has been defined as a “warm” talkgroup. At this point, thesatellite(s) 110 that is/are currently providing beams covering thecoverage area may establish control channel(s) for the particulartalkgroup, such that the control channel(s) for the talkgroup are activethroughout the entire coverage area defined for the particulartalkgroup, for example, even without a communication device provisionedto participate in the talkgroup having requested the instantiation ofthe talkgroup. In certain implementations, the satellite(s) 110 mayaccomplish this by setting up a control channel within each beamproviding coverage of the defined coverage area for the talkgroup. Insome implementations, such control channel(s) may be unique to the“warm” talkgroup and may not be used by other talkgroups. In otherimplementations, such control channel(s) may support a plurality oftalkgroups.

If the satellite-based PTT system is implemented using anon-geostationary satellite constellation (e.g., a LEO satelliteconstellation), as the satellite(s) 110 move away from and stopproviding coverage for the defined geographic area, those satellite(s)110 may handoff the control channel(s) to other satellite(s) 110 as theybegin to cover the defined coverage area for the talkgroup. Such othersatellites may begin to provide the control channel(s) when they startproviding coverage for the defined coverage area for the talkgroup. Inthis manner, the satellites 110 may share responsibility for maintainingcontinuously available control channels for the “warm” talkgroup in thedefined coverage area for the talkgroup.

In S408, a communication device 150 may make a request to instantiatethe “warm” talkgroup. In particular implementations, a communicationdevice 150 provisioned to participate in the talkgroup and disposed inthe defined coverage area may access the control channel for the “warm”talkgroup of the beam currently covering the communication device 150and use the control channel to transmit a request to instantiate the“warm” talkgroup to the satellite 110 providing the control channel. Inalternative implementations, the communication device 150 may transmitthe request to instantiate the talkgroup to the satellite 110 using adifferent channel than the control channel.

In S410, the request to instantiate the “warm” talkgroup may be passedto the management center 130, and device 120 may control thesatellite(s) 110 currently providing coverage of the defined coveragearea for the talkgroup to allocate traffic channel(s) for the “warm”talkgroup within the beams that are covering the defined coverage areafor the talkgroup. In some implementations, the satellite 110 thatreceives the request to instantiate the “warm” talkgroup (and othersatellite(s) 110 currently providing coverage of the defined coveragearea for the talkgroup) may allocate one or more additional channels touse as traffic channels for the “warm” talkgroup based on the requestwithout passing the request to management center 130. In addition, suchsatellite(s), with or without instruction from management 130, maytransmit signaling information in the control channel(s) for thetalkgroup identifying the traffic channel(s) that have been allocatedfor the talkgroup so that the communication devices 150 provisioned toparticipate in the talkgroup know which traffic channel(s) to access toparticipate in the talkgroup. Further, as satellite(s) 110 orbit theymay handoff responsibility for providing the traffic channels for thetalkgroup in a manner similar to that described above for S406 withrespect to the control channel(s).

In S412, device 120 at the management center 130 may determine whetherthe particular talkgroup has become inactive (e.g., whethercommunication is no longer taking place via the particular talkgroup).In certain implementations, one or more of the satellites 110 or themanagement center 130 itself may make the determination of S412 insteadof device 120. If the particular talkgroup is still active (S412: No),the determination of S412 may be repeated periodically until theparticular talkgroup becomes inactive. Alternatively, if the particulartalkgroup has become inactive (S412: Yes), the process may proceed toS414.

In S414, device 120 may instruct the satellite(s) 110 providing thetraffic channels for the particular talkgroup to tear down (e.g.,reallocate or terminate) the traffic channels for the particulartalkgroup. Consequently, the satellite(s) 110 may tear down the trafficchannels for the particular talkgroup. Nevertheless, because theparticular talkgroup was defined as a “warm” talkgroup by theadministrators, the satellite(s) 110 may not tear down the controlchannel(s) for the particular talkgroup. Thus, control channel(s) forthe talkgroup may be maintained continuously throughout the coveragearea defined for the talkgroup even though the talkgroup no longer isactive. The process then may return to S408 and wait for another requestto instantiate the particular (e.g. “warm”) talkgroup.

As described above, talkgroups may be used to transfer voicecommunications or data communications. In some implementations,talkgroups may function as a broadcast mechanism for transmittingpackets of information. In some implementations, the packets ofinformation may include sound data that may be used to implement voicecommunication. In other implementations, the packets of information mayinclude data representing other media, such as text, software, videos,and webpages, for example. In still other implementations, sometalkgroups may carry packets of information including sound data andother talkgroups may carry packets of information including datarepresenting other media, or talkgroups may be dynamically reallocatedto carry these different types of data packets as needed. In someimplementations, the PTT administrator may dynamically reallocatetalkgroups between voice communication and data communication at themanagement center. In other implementations, users of communicationdevices may dynamically reallocate talkgroups between voicecommunication and data communication at the communication devicesthemselves.

For example, a particular talkgroup may be responsible for transmittingcritical information or software to communication devices in a PTTnetwork. In certain implementations, this talkgroup may be assigned as a“warm” talkgroup, such that startup latency associated withinstantiating the talkgroup will be reduced and the critical informationor software will be pushed out quickly.

For example, an oil pipeline may include different monitoring devicesand valves may be spread along the pipeline, each containingcommunication devices provisioned to utilize a particular talkgroup. Ifa valve malfunctions, it may be critical that the associated monitoringdevice warns the pipeline operator and/or the other valves, such thatthe other valves can take appropriate actions to prevent the malfunctionfrom cascading. By using a “warm” talkgroup, the talkgroup may beinstantiated more rapidly, for example, than in the case of a “cold”talkgroup, and the pipeline operator and other valves may receive thewarning sooner and have more time to prevent the malfunction fromcascading.

Another example implementation of “warm” talkgroups may involve militaryapplications. For example, a military user of a satellite-based PTTnetwork may need to rapidly communicate information about a hostileengagement, but continuously-maintained “hot” talkgroups may not befeasible for security reasons or may be too resource intensive.Consequently, a “warm” talkgroup may be utilized to reduce latency andavoid security issues or resource inefficiency related to acontinuously-maintained “hot” talkgroup.

FIG. 5A shows a schematic diagram of a mobile communication deviceconfigured to participate in a satellite communication system,including, for example, a satellite-based PTT system, in accordance withparticular implementations of the present disclosure. Communicationdevice 150 may include a central processing unit (“CPU”) 701A, a memory702A, and an input/output (“I/O”) device 703A.

Memory 702A may store computer-readable instructions that may instructCPU 701A to perform certain processes. Memory 702A may comprise, forexample, RAM, ROM, EPROM, Flash memory, a hard disk drive, a solid statedrive, or any suitable combination thereof. When executed by CPU 701A,the computer-readable instructions stored in memory 702A may instructCPU 701A to operate as one or more devices configured to performparticular functions. In certain implementations, memory 702A may storecomputer-readable instructions for performing any and all functions orprocesses described herein, and CPU 701A may execute suchcomputer-readable instructions and operate as one or more devicesconfigured to perform or control such functions or processes. Memory702A may store data, such as position information, information aboutprovisioned talkgroups, or connection information associated withnetwork 100, for example.

CPU 701A may execute the computer-readable instructions stored in memory702A, and the computer-readable instructions may instruct CPU 701A toperform or control a plurality of processes including, but not limitedto, one or more of the processes described with respect to FIGS. 3 and 4and any other process described herein. Accordingly, CPU 701A may beconfigured to perform a variety of processes, as discussed above in moredetail. For example, CPU 701A may be a processor, a controller, anapplication specific integrated circuit (“ASIC”), or a system comprisinga plurality of processors, controllers, or ASICs.

I/O device 703A may receive one or more of data from network 100, datafrom one or more other devices connected to communication device 150,and input from a user and provide such information to CPU 701A and/ormemory 702A. I/O device 703A may transmit data to network 100, maytransmit data to one or more other devices connected to communicationdevice 150, and may transmit information to a user (e.g., display theinformation or indicators thereof, provide audible indications of suchinformation). I/O device 703A may include, for example, one or more of atransceiver, a modem, a network card, a transmitter, a receiver, amicrophone, a speaker, an antenna, a light-emitting diode (“LED”), adisplay device, or any other device configured to provide or receiveinformation.

FIG. 5B shows a schematic illustration of a device 120 configured toimplement one or processes for managing communication in a satellitecommunication system, including, for example, a satellite-based PTTsystem, in accordance with particular implementations of the presentdisclosure. Device 120 may include a CPU 701B, a memory 702B, and an I/Odevice 703B. In some implementations, CPU 701B, a memory 702B, and anI/O device 703B may function similarly to CPU 701A, a memory 702A, andan I/O device 703A. In other implementations, CPU 701B, a memory 702B,and an I/O device 703B may have functionalities different from CPU 701A,a memory 702A, and an I/O device 703A.

Memory 702B may store computer-readable instructions that may instructCPU 701B to perform certain processes. Memory 702B may comprise, forexample, RAM, ROM, EPROM, Flash memory, a hard disk drive, a solid statedrive, or any suitable combination thereof. When executed by CPU 701B,the computer-readable instructions stored in memory 702B may instructCPU 701B to operate as one or more devices configured to performparticular functions. In certain implementations, memory 702B may storecomputer-readable instructions for performing any and all functions orprocesses described herein, and CPU 701B may execute suchcomputer-readable instructions and operate as one or more devicesconfigured to perform or control such functions or processes. Memory702B may store data, such as position information, information aboutprovisioned talkgroups, information about communication devices 150, oroperational information associated with network 100, for example.

CPU 701B may execute the computer-readable instructions stored in memory702B, and the computer-readable instructions may instruct CPU 701B toperform or control a plurality of processes including, but not limitedto, one or more of the processes described with respect to FIGS. 3 and 4and any other process described herein. Accordingly, CPU 701B may beconfigured to perform a variety of processes, as discussed above in moredetail. For example, CPU 701B may be a processor, a controller, an ASIC,or a system comprising a plurality of processors, controllers, or ASICs.

I/O device 703B may receive one or more of data from network 100, datafrom one or more other devices connected to communication device 120,and input from a user and provide such information to CPU 701B and/ormemory 702B. I/O device 703B may transmit data to network 100, maytransmit data to one or more other devices connected to communicationdevice 120, and may transmit information to a user (e.g., display theinformation or indicators thereof, provide audible indications of suchinformation). I/O device 703B may include, for example, one or more of atransceiver, a modem, a network card, a transmitter, a receiver, amicrophone, a speaker, an antenna, a LED, a display device, or any otherdevice configured to provide or receive information.

The flowcharts and diagrams in FIGS. 1-4 and 5A-5B illustrate examplesof the architecture, functionality, and operation of possibleimplementations of systems, methods and computer program productsaccording to various aspects of the present disclosure. In this regard,each block in the flowcharts or block diagrams may represent a module,segment, or portion of code, which comprises one or more executableinstructions for implementing the specified logical function(s). Itshould also be noted that, in some alternative implementations, thefunctions noted in the block may occur out of the order noted in thefigures. For example, two blocks shown in succession may, in fact, beexecuted substantially concurrently, or the blocks may sometimes beexecuted in the reverse order, depending upon the functionalityinvolved. It will also be noted that each block of the block diagramsand/or flowchart illustration, and combinations of blocks in the blockdiagrams and/or flowchart illustration, can be implemented by specialpurpose hardware-based systems that perform the specified functions oracts, or combinations of special purpose hardware and computerinstructions.

The terminology used herein is for the purpose of describing particularaspects only and is not intended to be limiting of the disclosure. Asused herein, the singular forms “a,” “an,” and “the” are intended toinclude the plural forms as well, unless the context clearly indicatesotherwise. It will be further understood that the terms “includes,”“comprises,” “including,” and/or “comprising,” when used in thisspecification, specify the presence of stated features, integers, steps,operations, elements, and/or components, but do not preclude thepresence or addition of one or more other features, integers, steps,operations, elements, components, and/or groups thereof. Moreover, asused herein, the term “user” is intended to refer to one or more of aperson, an organization, a computer, or any other entity, apparatus,device, or system.

For example, the terms “communication device,” “communication system,”“device,” and “system” may generally refer to and include satellites110, satellite links 115, operation hubs 130, devices or systemsconnected with clouds 140, devices 120, gateways 135, communicationdevices 150, or any other devices or systems that facilitate thecommunication of information. Moreover, the terms “management center,”“management device,” and “management system” may generally refer to andinclude satellites 110, satellite links 115, management center 130,devices or systems connected with clouds 140, devices 120, gateways 135,communication devices 150, or any other devices or systems thatfacilitate managing the communication of information. In addition, theterm “satellite constellation” may refer to a single satellite or to aplurality of satellites.

While the techniques and implementations disclosed herein have generallybeen described in the context of satellite-based PTT communication, suchtechniques and implementations may readily be applied to othercommunication systems. For example, the techniques and implementationsdisclosed herein may be applied to cellular-based PTT communicationsystems, other terrestrial-based PTT communication systems, land mobileradio (“LMR”) communication systems, hybrid communication systems usingone or more of the communication systems described herein or apparent toone of skill in the art, or any other communication systems conceivableby one of skill in the art.

Aspects of the present disclosure may be illustrated and describedherein in any of a number of patentable classes or contexts includingany new and useful process, machine, manufacture, or composition ofmatter, or any new and useful improvement thereof. Accordingly, aspectsof the present disclosure may be implemented entirely in hardware,entirely in software (including firmware, resident software, micro-code,etc.) or in combinations of software and hardware that may all generallybe referred to herein as a “circuit,” “module,” “component,” or“system.” Furthermore, aspects of the present disclosure may take theform of a computer program product embodied in one or morecomputer-readable media having computer-readable program code embodiedthereon.

Any combination of one or more computer-readable media may be utilized.The computer-readable media may be a computer-readable signal medium ora computer-readable storage medium. A computer-readable storage mediummay be, for example, but not limited to, an electronic, magnetic,optical, electromagnetic, or semiconductor system, apparatus, or device,or any suitable combination of the foregoing. More specific examples (anon-exhaustive list) of such a computer-readable storage medium includethe following: a portable computer diskette, a hard disk, a randomaccess memory (“RAM”), a read-only memory (“ROM”), an erasableprogrammable read-only memory (“EPROM” or Flash memory), an appropriateoptical fiber with a repeater, a portable compact disc read-only memory(“CD-ROM”), an optical storage device, a magnetic storage device, or anysuitable combination of the foregoing. In the context of this document,a computer-readable storage medium may be any tangible medium that cancontain, or store a program for use by or in connection with aninstruction execution system, apparatus, or device.

A computer-readable signal medium may include a propagated data signalwith computer-readable program code embodied therein, for example, inbaseband or as part of a carrier wave. Such a propagated signal may takeany of a variety of forms, including, but not limited to,electro-magnetic, optical, or any suitable combination thereof. Acomputer-readable signal medium may be any computer-readable medium thatis not a computer-readable storage medium and that can communicate,propagate, or transport a program for use by or in connection with aninstruction execution system, apparatus, or device. Program codeembodied on a computer-readable signal medium may be transmitted usingany appropriate medium, including but not limited to satellitecommunications, wireless, wireline, optical fiber cable, RF signals,etc., or any suitable combination of the foregoing.

Computer program code for carrying out operations for aspects of thepresent disclosure may be written in any combination of one or moreprogramming languages, including an object oriented programminglanguage, such as JAVA, C++, C#, or other suitable programminglanguages. The program code may execute entirely on a user's device,partly on a user's device, as a stand-alone software package, partly ona user's device and partly on a remote computer, or entirely on a remotecomputer or server. In the latter scenario, a remote computer may beconnected to a user's device through any type of network, including asatellite communications network, a local area network (“LAN”), or awide area network (“WAN”), or the connection may be made to an externalcomputer (for example, through the Internet using an Internet ServiceProvider) or offered as a service, such as, for example, a Software as aService (“SaaS”), e.g., over a secure web interface via a httpsconnection.

Aspects of the present disclosure are described herein with reference toflowchart illustrations and/or block diagrams of methods, apparatuses(including systems), and computer program products. Individual blocks ofthe flowchart illustrations and/or block diagrams, and combinations ofblocks in the flowchart illustrations and/or block diagrams, can beimplemented by computer program instructions. These computer programinstructions may be provided to a processor of a general purposecomputer, special purpose computer, or other programmable dataprocessing apparatus to produce a machine, such that the instructions,which execute via the processor of the computer or other programmableinstruction execution apparatus, create a mechanism for implementing thefunctions/acts specified in the flowchart and/or block diagram block orblocks.

These computer program instructions may also be stored in acomputer-readable medium. When accessed from the computer-readablemedium and executed, the computer program instructions may direct acomputer, other programmable data processing apparatus, or other devicesto function in a particular manner, such that the instructions whenstored in the computer-readable medium produce an article of manufactureincluding instructions that, when executed, cause a computer toimplement the function/act specified in the flowchart and/or blockdiagram block or blocks. The computer program instructions may also beloaded onto a computer, other programmable instruction executionapparatus, or other devices to cause a series of operational steps to beperformed on the computer, other programmable apparatuses or otherdevices to produce a computer implemented process such that theinstructions which execute on the computer or other programmableapparatus provide processes for implementing the functions/actsspecified in the flowchart and/or block diagram block or blocks.

The corresponding structures, materials, acts, and equivalents of anymeans or step plus function elements in the claims below are intended toinclude any disclosed structure, material, or act for performing thefunction in combination with other claimed elements as specificallyclaimed. The description of the present disclosure has been presentedfor purposes of illustration and description, but is not intended to beexhaustive or limited to the disclosure in the form disclosed. Manymodifications and variations will be apparent to those of ordinary skillin the art without departing from the scope and spirit of thedisclosure. The aspects of the disclosure herein were chosen anddescribed in order to explain the principles of the disclosure and thepractical application, and to enable others of ordinary skill in the artto understand the disclosure with various modifications as are suited tothe particular use contemplated.

What is claimed is:
 1. A method implemented by a satellitecommunications system, the method comprising: maintaining one or morecontrol channels for transmitting information related to correspondingtalkgroups supported by the satellite communications system, at leastone of the control channels being a first talkgroup control channel fortransmitting information related to a first talkgroup that is notinstantiated; receiving a request to instantiate the first talkgroupfrom a communications device provisioned to participate in the firsttalkgroup; in response to receiving the request to instantiate the firsttalkgroup: establishing one or more first talkgroup traffic channels fortransmitting communications between communications devices provisionedto participate in the first talkgroup, and supporting transmission, viathe first talkgroup control channel, of information facilitating accessto the one or more first talkgroup traffic channels by communicationsdevices provisioned to participate in the first talkgroup; receiving arequest to instantiate a second talkgroup that is different than thefirst talkgroup from a communications device provisioned to participatein the second talkgroup; and in response to receiving the request toinstantiate the second talkgroup: establishing a second talkgroupcontrol channel for transmitting information related to the secondtalkgroup; establishing one or more second talkgroup traffic channelsfor transmitting communications between communications devicesprovisioned to participate in the second talkgroup, and supportingtransmission, via the second talkgroup control channel, of informationfacilitating access to the one or more second talkgroup traffic channelsby communications devices provisioned to participate in the secondtalkgroup.
 2. The method of claim 1 further comprising: determining toterminate the instantiation of the first talkgroup; in response todetermining to terminate the instantiation of the first talkgroup,discontinuing the one or more first talkgroup traffic channels whilecontinuing to maintain the first talkgroup control channel; determiningto terminate the instantiation of the second talkgroup; and in responseto determining to terminate the instantiation of the second talkgroup,discontinuing the one or more second talkgroup traffic channels and thesecond talkgroup control channel.
 3. The method of claim 1 wherein:maintaining the first talkgroup control channel for transmittinginformation related to a first talkgroup that is not instantiatedincludes maintaining a first talkgroup control channel for transmittinginformation related to the first talkgroup between at least onesatellite and a communications device provisioned to participate in thefirst talkgroup; establishing one or more first talkgroup trafficchannels for transmitting communications between communications devicesprovisioned to participate in the first talkgroup includes establishingone or more first talkgroup traffic channels for transmittingcommunications between one or more satellites and communications devicesprovisioned to participate in the first talkgroup; establishing a secondtalkgroup control channel for transmitting information related to thesecond talkgroup includes establishing a second talkgroup controlchannel for transmitting information related to the second talkgroupbetween at least one satellite and a communications device provisionedto participate in the second talkgroup; and establishing one or moresecond talkgroup traffic channels for transmitting communicationsbetween communications devices provisioned to participate in the secondtalkgroup includes establishing one or more second talkgroup trafficchannels for transmitting communications between one or more satellitesand communications devices provisioned to participate in the secondtalkgroup.
 4. The method of claim 1 wherein: supporting transmission,via the first talkgroup control channel, of information facilitatingaccess to the one or more first talkgroup traffic channels bycommunications devices provisioned to participate in the first talkgroupincludes transmitting, from one or more satellites via the firsttalkgroup control channel, information facilitating access to the one ormore first talkgroup traffic channels by communications devicesprovisioned to participate in the first talkgroup; and supportingtransmission, via the second talkgroup control channel, of informationfacilitating access to the one or more second talkgroup traffic channelsby communications devices provisioned to participate in the secondtalkgroup includes transmitting, from one or more satellites via thesecond talkgroup control channel, information facilitating access to theone or more second talkgroup traffic channels by communications devicesprovisioned to participate in the second talkgroup.
 5. The method ofclaim 4 wherein: transmitting, from one or more satellites via the firsttalkgroup control channel, information facilitating access to the one ormore first talkgroup traffic channels by communications devicesprovisioned to participate in the first talkgroup includes transmittinginformation that identifies a traffic channel as one of the firsttalkgroup traffic channels; and transmitting, from one or moresatellites via the second talkgroup control channel, informationfacilitating access to the one or more second talkgroup traffic channelsby communications devices provisioned to participate in the secondtalkgroup includes transmitting information that identifies a differenttraffic channel as one of the second talkgroup traffic channels.
 6. Themethod of claim 1 wherein: supporting transmission, via the firsttalkgroup control channel, of information facilitating access to the oneor more first talkgroup traffic channels by communications devicesprovisioned to participate in the first talkgroup includes receiving, byat least one satellite via the first talkgroup control channel,information related to accessing one of the first talkgroup trafficchannels from at least one communications device provisioned toparticipate in the first talkgroup; and supporting transmission, via thesecond talkgroup control channel, of information facilitating access tothe one or more second talkgroup traffic channels by communicationsdevices provisioned to participate in the second talkgroup includesreceiving, by at least one satellite via the second talkgroup controlchannel, information related to accessing one of the second talkgrouptraffic channels from at least one communications device provisioned toparticipate in the second talkgroup.
 7. A system comprising: acommunications network including at least one satellite; and a computingsystem configured to: cause one or more satellites to maintain one ormore control channels for transmitting information related tocorresponding talkgroups supported by the communications network, atleast one of the control channels being a first talkgroup controlchannel for transmitting information related to a first talkgroup thatis not instantiated; in response to receiving a request to instantiatethe first talkgroup from a communications device provisioned toparticipate in the first talkgroup: cause one or more satellites toestablish one or more first talkgroup traffic channels for transmittingcommunications between communications devices provisioned to participatein the first talkgroup, and cause at least one satellite to supporttransmission, via the first talkgroup control channel, of informationfacilitating access to the one or more first talkgroup traffic channelsby communications devices provisioned to participate in the firsttalkgroup; in response to receiving a request to instantiate a secondtalkgroup that is different than the first talkgroup from acommunications device provisioned to participate in the secondtalkgroup: cause one or more satellites to establish a second talkgroupcontrol channel for transmitting information related to the secondtalkgroup; cause one or more satellites to establish one or more secondtalkgroup traffic channels for transmitting communications betweencommunications devices provisioned to participate in the secondtalkgroup, and cause at least one satellite to support transmission, viathe second talkgroup control channel, of information facilitating accessto the one or more second talkgroup traffic channels by communicationsdevices provisioned to participate in the second talkgroup.
 8. Thesystem of claim 7 wherein: the computing system is configured to causeat least one satellite to support transmission, via the first talkgroupcontrol channel, of information facilitating access to the one or morefirst talkgroup traffic channels by communications devices provisionedto participate in the first talkgroup by causing at least one satelliteto transmit information facilitating access to the one or more firsttalkgroup traffic channels by communications devices provisioned toparticipate in the first talkgroup; and the computing system isconfigured to cause at least one satellite to support transmission, viathe second talkgroup control channel, of information facilitating accessto the one or more second talkgroup traffic channels by communicationsdevices provisioned to participate in the second talkgroup by causing atleast one satellite to transmit information facilitating access to theone or more second talkgroup traffic channels by communications devicesprovisioned to participate in the second talkgroup.
 9. The system ofclaim 8 wherein: the computing system configured to cause at least onesatellite to transmit information facilitating access to the one or morefirst talkgroup traffic channels by communications devices provisionedto participate in the first talkgroup comprises a computing systemconfigured to transmit information that identifies a traffic channel asone of the first talkgroup traffic channels; and the computing systemconfigured to cause at least one satellite to transmit informationfacilitating access to the one or more second talkgroup traffic channelsby communications devices provisioned to participate in the secondtalkgroup comprises a computing system configured to transmitinformation that identifies a different traffic channel as one of thesecond talkgroup traffic channels.
 10. A method implemented by asatellite communications system, the method comprising: maintaining oneor more control channels for transmitting information related tocorresponding talkgroups supported by the satellite communicationssystem, at least one of the control channels being a control channel fortransmitting information related to a particular talkgroup that is notinstantiated; receiving a request to instantiate the particulartalkgroup from a communications device provisioned to participate in theparticular talkgroup; in response to receiving the request toinstantiate the particular talkgroup: establishing one or moreparticular talkgroup traffic channels for transmitting communicationsbetween communications devices provisioned to participate in theparticular talkgroup, and supporting transmission, via the particulartalkgroup control channel, of information facilitating access to the oneor more particular talkgroup traffic channels by communications devicesprovisioned to participate in the particular talkgroup; determining toterminate the instantiation of the particular talkgroup; and in responseto determining to terminate the instantiation of the particulartalkgroup, discontinuing the one or more traffic channels whilecontinuing to maintain the particular talkgroup control channel.
 11. Themethod of claim 10 wherein determining to terminate the instantiation ofthe particular talkgroup includes: receiving an instruction to terminatethe instantiation of the particular talkgroup from a communicationsdevice provisioned to participate in the particular talkgroup; anddetermining to terminate the instantiation of the particular talkgroupin response to receiving the instruction.
 12. The method of claim 10wherein determining to terminate the instantiation of the particulartalkgroup includes: determining that the particular talkgroup has becomeinactive; and determining to terminate the instantiation of theparticular talkgroup in response to determining that the particulartalkgroup has become inactive.
 13. The method of claim 10 whereinsupporting transmission, via the particular talkgroup control channel,of information facilitating access to the one or more particulartalkgroup traffic channels by communications devices provisioned toparticipate in the particular talkgroup includes transmitting, from oneor more satellites via the particular talkgroup control channel,information that identifies a traffic channel as one of the particulartalkgroup traffic channels.
 14. A system comprising: a communicationsnetwork including at least one satellite; and a computing systemconfigured to: cause one or more satellites to maintain one or morecontrol channels for transmitting information related to correspondingtalkgroups supported by the communications network, at least one of thecontrol channels being a control channel for transmitting informationrelated to a particular talkgroup that is not instantiated; in responseto receiving a request to instantiate the particular talkgroup from acommunications device provisioned to participate in the particulartalkgroup: cause one or more satellites to establish one or moreparticular talkgroup traffic channels for transmitting communicationsbetween communications devices provisioned to participate in theparticular talkgroup, and cause at least one satellite to supporttransmission, via the particular talkgroup control channel, ofinformation facilitating access to the one or more particular talkgrouptraffic channels by communications devices provisioned to participate inthe particular talkgroup; determine to terminate the instantiation ofthe particular talkgroup; and in response to determining to terminatethe instantiation of the particular talkgroup: cause the one or moresatellites to discontinue the one or more traffic channels, and causethe at least one satellite to continue to maintain the particulartalkgroup control channel.
 15. The system of claim 14 wherein thecomputing system configured to determine to terminate the instantiationof the particular talkgroup is configured to determine to terminate theinstantiation of the particular talkgroup in response to receiving aninstruction to terminate the instantiation of the particular talkgroupfrom a communications device provisioned to participate in theparticular talkgroup.
 16. The system of claim 14 wherein the computingsystem configured to determine to terminate the instantiation of theparticular talkgroup is configured to determine to terminate theinstantiation of the particular talkgroup by: determining that theparticular talkgroup has become inactive; and determining to terminatethe instantiation of the particular talkgroup in response to determiningthat the particular talkgroup has become inactive.
 17. The system ofclaim 14 wherein the computing system configured to cause at least onesatellite to support transmission, via the particular talkgroup controlchannel, of information facilitating access to the one or moreparticular talkgroup traffic channels by communications devicesprovisioned to participate in the particular talkgroup comprises acomputing system configured to cause at least one satellite to transmit,via the particular talkgroup control channel, information thatidentifies a traffic channel as one of the particular talkgroup trafficchannels.
 18. A method implemented by a communications system, themethod comprising: maintaining one or more control channels fortransmitting information related to corresponding talkgroups supportedby the communications system, at least one of the control channels beinga control channel for transmitting information related to a particulartalkgroup that is not instantiated; receiving a request to instantiatethe particular talkgroup from a communications device provisioned toparticipate in the particular talkgroup; and in response to receivingthe request to instantiate the particular talkgroup: establishing one ormore traffic channels for transmitting communications betweencommunications devices provisioned to participate in the particulartalkgroup, and supporting transmission, via the control channel for theparticular talkgroup, of information facilitating access to the one ormore particular talkgroup traffic channels by communications devicesprovisioned to participate in the particular talkgroup.
 19. A systemcomprising: a communications network including multiple satellites; anda computing system configured to: determine that a first satellite ofthe communications network is responsible for providing talkgroupcoverage for a geographic area; in response to determining that thefirst satellite is responsible for providing talkgroup coverage for thegeographic area, control the first satellite to light up one or morecontrol channels related to the talkgroup in the geographic area;determine that the first satellite has moved to a new location such thatthe first satellite is no longer responsible for providing talkgroupcoverage for the geographic area; in response to determining that thefirst satellite has moved to the new location such that the firstsatellite is no longer responsible for providing talkgroup coverage forthe geographic area: determine that a second satellite of thecommunications network is responsible for providing talkgroup coveragefor the geographic area; control the second satellite to light up theone or more control channels in the geographic area; and control thefirst satellite to stop lighting up the one or more control channels inthe geographic area; in response to receiving a request to instantiatethe talkgroup, control one or more satellites of the communicationsnetwork to light up one or more traffic channels in the geographic area,the one or more traffic channels being traffic channels for thetalkgroup; determine that the talkgroup is inactive; and in response todetermining that the talkgroup is inactive, control one or moresatellites of the communications network to stop lighting up the one ormore traffic channels in the geographic area while continuing to lightup the one or more control channels related to the talkgroup in thegeographic area.
 20. A system comprising: a communications networkincluding multiple satellites; and a computing system configured to: inresponse to receiving information specifying that a talkgroup is a“warm” talkgroup, control one or more satellites of the communicationsnetwork to light up one or more control channels for the talkgroup; inresponse to receiving a request to instantiate the talkgroup, controlone or more satellites of the communications network to: light up one ormore traffic channels for the talkgroup, and transmit, via the one ormore control channels, information for facilitating access to the one ormore traffic channels for the talkgroup; determine that the talkgroup isinactive; and in response to determining that the talkgroup is inactive,control one or more satellites of the communications network to stoplighting up the one or more traffic channels for the talkgroup whilecontinuing to light up the one or more control channels for thetalkgroup.